He was inspired to enter film industry also due to the fact that the crew members of Muthal Mariyathai including director Bharathiraja, music composer Ilaiyaraaja and lyricist Vairamuthu were hailing from Theni district as it was Marimuthu's birthplace.
[5] After initially working as a waiter in hotels, he became acquainted with lyricist Vairamuthu through their common interest in literature, before becoming an assistant director with Rajkiran for his films Aranmanai Kili (1993) and Ellame En Rasathan (1995).
[6] Marimuthu then continued to work as an assistant director with filmmakers such as Mani Ratnam, Vasanth, Seeman, Rajiv Menon and S. J. Surya, before co-directing Silambarasan's film Manmadhan (2004).
[7] He notably worked as an assistant director for Aasai (1995), Nerrukku Ner (1997), Vaali (1999), Poovellam Kettuppar (1999), Kushi (2000), Rhythm (2000), Udhaya (2004), New (2004), and Anbe Aaruyire (2005).
[9] Moviebuzz noted "Marimuthu is a welcome addition to the brave new directors in Tamil cinema, who are trying their best within the commercial format to give a different type of love story".
He played negative role in Nelson Dilipkumar's directorial Jailer (2023), which eventually marked his last feature film prior to his untimely death.